The present invention relates to a hand held machine tool intended for grinding and like operations.
In particular, the invention concerns a machine tool having a housing and a motor attached thereto for rotating a tool carrying output spindle. The motor is supported by the housing via a forward bearing unit including resilient means for absorbing radial displacements due to spindle vibrations and a rear bearing unit substantially non-resilient to radial displacement of the spindle.
Previous machines of this type have been effective in reducing the vibrations transferred to the housing or base structure but they have not been suitable for use as hand held tools. The main reason for that is their comparatively high weight and large outer dimensions due to separation of the output spindle and the rotor of the drive motor. Another reason is that their forward bearing means have not been able to transfer axial load and at the same time provide a low spring constant resiliency to radial vibrations.
The above problems are solved by the present invention which is intended to accomplish a vibration insulated machine tool suitable for use in hand held tool applications.